Duodenal stenosis caused by locally advanced upper tract urothelial carcinoma: a case report.

Duodenal stenosis caused by upper tract urothelial carcinoma (UTUC) is rare. A 70-year-old male patient was diagnosed with a UTUC invading the duodenum 3 months before admission. Owing to duodenal stenosis, enteral nutrition was necessary. We performed pancreaticoduodenectomy with right nephroureterectomy and right hemicolectomy using a multi-disciplinary approach. Postoperative pathology revealed a UTUC invading the right kidney, duodenum, pancreas, and transverse colon. The patient underwent chemotherapy and immunotherapy after surgery, which improved his quality of life.